According to a study published in Science Advances, a scientific journal, a team of European astronomers has proved that water, in the form of ‘pebble snow’, can be delivered to any terrestrial planet.

This has to be done in the early phases of that planet’s growth. As water is known to be one of Earth’s building blocks, it could be the source of life for another. Water molecules occur frequently in nature, so there is a high chance that they will occur on all planets of the Milky Way. What determines whether water in the liquid form is present on a planet is its distance from its star.

Scientists have used a computer model to calculate how much time it takes for planets to form, and which building blocks play a role in their creation. Their results show that 4.5 billion years ago, dust particles of ice and carbon as small as a millimetre lead to the formation of Earth.

It is believed that Earth had grown by capturing masses of ice and carbon pebbles till it had grown to about 1% of its current mass. It then started to grow faster and faster until it reached its current mass five million years later. Sometime in-between, the temperature of the Earth’s surface rose sharply, causing the ice trapped in the pebbles to evaporate while falling to the surface. This is why only 0.1% of the Earth constitutes water, even though 70% of our planet’s surface is covered by water.

Since the water molecule is present everywhere in our home galaxy, it is possible that other planets could have been created in the same way as Mars, Venus and Earth did. It is also highly likely that life may be present on some of these planets, provided that the temperature is ideal.

If all the planets in our galaxy have the same temperature conditions and building blocks and as that of Earth, there is a good chance that they may not only have water but also continents. However, if it was random how much amount of water there was on planets, they may look very different from one another. While some planets would simply be too dry for life to develop, others would be submerged in water with zero landmasses.